Carboxymethylcellulose (CMC) is a water soluble, biocompatible and bioresorbable semi-synthesized polysaccharide. The safety of commercially available CMC having high purity has been identified and approved by the Food and Drug Administration (FDA) for incorporation into many products. CMC is able to react with various polymers by way of electrostatic interaction, ionic cross-linking, hydrogen bonding, Van der Waals interactions, and physical interpenetration. Because of its safety, convenience and diversity of physico-chemical properties, CMC has demonstrated applications in the pharmaceutical, food and cosmetic industries.
CMC is one type of carboxypolysaccharide (CPS). CPSs have also been used in the manufacture of implantable polymers. CPSs are polymers made of saccharide monomers in which some of the hydroxyl (—OH) groups are replaced with carboxyl groups (—COOH or COO—). Thus, CPSs such as CMC have some hydroxyl groups and some carboxyl groups present. Carboxylation can permit ionic interaction within a polymer chain or can permit interaction between polymer chains, thereby forming a gel. Such gels have been used for a variety of applications, including implantable medical polymers.
Polyethers (PE) are polymers made of chains of ether residues (—CH2—CH2—). Polyethylene Oxide (PEO) is a polymer made with PE having hydroxyl groups. PEOs can therefore form hydrogen bonds with carboxyl groups on CPSs, thereby forming a hydrogen-bonded composition. More generally, polyalkylene oxides (POs or PAOs) can react in similar fashions with CPSs to form hydrogen bonded cross-linked compositions.
Adhesions are unwanted tissue growths occurring between layers of adjacent bodily tissue or between tissues and internal organs. Adhesions commonly form during the healing which follows surgical procedures, and when present, adhesions can prevent the normal motions of those tissues and organs with respect to their neighboring structures.
The medical and scientific communities have studied ways of reducing the formation of post-surgical adhesions by the use of high molecular weight carboxyl-containing biopolymers. These biopolymers can act as physical barriers to separate tissues from each other during healing, so that adhesions between normally adjacent structures do not form.